Field of the Invention
The present invention relates to a fuel tank which lowers pressure, when compressed natural gas or hydrogen gas is stored, to assure stability and to improve fuel adsorption efficiency.
Description of Related Art
In general, a high pressure vessel, such as a fuel tank of a natural gas vehicle or a hydrogen tank of a fuel cell vehicle, compresses natural gas or hydrogen gas fuel to a high pressure and then stores the compressed fuel. A high pressure vessel decompresses compressed fuel received therein and then provides decompressed fuel as fuel necessary for an engine.
Recently, as natural gas and hydrogen gas receive attention as future energy resources, development of vehicles driven using natural gas or hydrogen gas has been carried out. However, since, to store a sufficient amount of natural gas or hydrogen gas, fuel needs to be compressed to a high pressure and then stored, high pressure vessels require sufficient durability and, thus, high-priced high pressure vessels in consideration of material and stiffness have been produced.
To solve a problem, a high pressure vessel to store natural gas or hydrogen gas using an adsorbent has been developed. Thereby, according to lowering of storage pressure when natural gas or hydrogen gas is stored, manufacture of a high pressure vessel in consideration of material and stiffness is not greatly restricted and the danger of explosion due to accidents is greatly lowered.
However, in a high pressure vessel using an adsorbent, adsorption efficiency is important. However, techniques to improve adsorption efficiency are insufficient and there are many problems in application of such techniques to actual vehicles.
Therefore, a technique to improve adsorption efficiency of an adsorbent is required.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.